Lord Falconer of Thoroton, QC, has become the latest in a long line of Labour Cabinet ministers brought face to face with the reality of the party’s tough talk on law and order: the prisons are full.

Tomorrow when the Ministry of Justice opens its doors in Victoria, it will confront the problem that has dogged Labour for ten years.

Prison overcrowding forced Jack Straw to introduce Home Detention Curfew, under which 2,000 to 3,000 low-risk prisoners are on early release at any one time.

But by the time John Reid arrived at the Home Office the situation was worse. Twice he was forced to bring in emergency measures to allow prisoners to be held in police cells because jails had run out of space. Prisoners were being bussed around England to any available cell.

Mr Reid was prepared to consider early release of prisoners but only as a last resort. The Lord Chief Justice was persuaded to write to judges reminding them that prisons should be reserved for serious offenders; prison governors were allowed to move low-risk offenders to open prisons to create more space in closed jails; prisoners can be held in court cells; and £23 million has been spent on holding hundreds of prisoners in cells at police stations. He announced an 8,000-space building programme. But the accommodation is not coming on stream fast enough. Last week the prison population reached a record 80,591, compared with 60,000 in 1997.

Ending jail for shoplifters or relaxing rules on prisoners who break the terms of their release on licence risks damaging Tony Blair’s reputation for being “tough on crime, tough on the causes of crime”. And it is not clear that that would be anything more than a short-term fix.

Officials keep focusing on changes to early-release schemes, which could mean thousands of nonviolent offenders leaving jail early.

It would involve the Government taking a huge political hit, but within Whitehall it is argued that it would be better than a series of flawed measures that do not solve the problem.